Mat detector for slug linecasting machines



0fl1, 1960 E. G. sHAFFsrALL I 2,955,703

MAT DETECTOR FOR SLUG LJNECAS'IING`- MACHINES Filed Feb. 17, 195e 3 Sheets-sheet 1 INVENTOR. IVE/nvr 6.A Swan-SML L MMWMM Oc't. ll, 1960 v E. G. sHAFFsTALL y MAT DETECTOR FOR SLUG LINECASTING MACHINES s sheets-sheet 2 Filed Feb. 17, 1958 INVENTOR.

l10n: M

INPUT PULSE nNeeLuNa c Pulsa L.... L .r m. Mw. W/m H ,nf .a a.

WY f w f Oct. 11,1960 l E. G. sHAr-'FsTALL 2,955,703 MAT DETECTOR FOR SLUG LINECASTING MACHINES Filed Feb. 173, 1.958 5 Sheets-Sheet 5 insee rr 6'. SMF/farm. L.

#fram/frs.

N% Ik m Vw. m .F N E im SE u En W rlw *E .FQ mw wv JQ www Y www .\N= ||||.H.. Y N` E. -lil ND Re NS NN N4 NQ w Y: f l f.. s W n 292. m H m f? i N- n m `U1:\ited States Patent Oiitice MAT DETECTOR FOR SLUG LINECSTING ACHINES Everett 'GL Shalfstall, Indianapolis,.lnd., assigner to Shaffstall Equipment, Inc., Indianapolis, Ind., a corporation of Indiana Filed Feb. 17,1958, Ser. No. 715,655

11 Claims. (Cl. 199-18) VThis invention relates generally to malfunction detection apparatus for slug linecasting machines, and in particular to malfunction detection apparatus adapted for use" with automatically operated linecasting machines.

To speed up. and render more convenient the setting yof type .by slug linecasting machines, it has become conventional to provide such machines with attachment devices which automatically operate the linecasting machine.v The mat releasing mechanism of machines provided with such attachment devices is operated in re-V sponse to a perforated tape fed into the attachment rather than by direct manual operation of the linecasting machine keyboard by an operator. These attachments permit operation of the linecasting machine at high speeds and with such high speed operation it becomes quite important to detect the occurrence of malfunctions in the linecasting machine as soon as possible after they occur.

The present invention is directed to a malfunction detection apparatus which is described as incorporated into a conventional Mergenthaler Linotype machine having a Teletypesetter attachment for automatically operating the Linotype machine. The present invention is so described since the Linotype and Teletypesetter are the most common forms of slug linecasting machines and automatic operating attachments, respectively. It will be understood that the invention could be used with machines other than Linotype machines equipped with Teletypesetter attachments provided they were equipped with similar component parts.

The operation of the Linotype machine and -of the Teletypesetter are not described in detail herein since these devices themselves are well known in the art and are but environment for the present invention. Detailed texts on the operation of the Linotype machine are commonly available, one such being the oicial Manual of Linotype Machine Principles, published by Mergenthaler Linotype Company, Brooklyn, N.Y. in 1940. The Teletypesetter attachment is described in detail in Teletypesetter Bulletins No. 1, dated 1939; No. 4, dated 1939; No. 6, dated January, 1938; No. 7, dated January, 1938; No. 9, dated March, 1941; No. 53, dated January, 1941; and No. 52, dated November, 1936, all published by Teletypesetter Corporation, 1400 Wrightwood Avenue, Chicago, Illinois, and in U.S. Patents No. 2,006,860; No. 2,057,652; No. 2,060,838 and No. 2,091,286. v

v In general the operation of the herein-described appa` ratus provides for closure of a switch each. time the matrix or mat releasing linkage on the Linotype machine is operated. This action provides an input pulse, starting a timing cycle by charging a first condenser and starting the charging of a second condenser, which will actuate ailockingelement ytostop operation of the machine inv Patented Oct.V v11, 1960 a predetermined time (of the order of milliseconds) if a mat fails to leave the magazine when called for by operation of the mat releasing linkage. The cancellation of this input pulse and the stopping of the timing cycle is accomplished by a photo-electric circuit. A mat leaving the magazine and breaking a light beam which scans the front of the magazine causes the photo-circuit to actuate two relays which discharge both the first and the second condensers. If a mat sticks part way out of the magazine, thus continuously obstructing the light beam, a safety circuit is closed, and when contact points located over the Teletypesetter elevator shaft areV closed by the rotation of this shaft at the end of the line being set, the locking element is actuated, stopping actuation of the Linotype machine. The machine is thus stopped immediately after assembly of a line in which one or more mats are missing. Should a line fail to cast, due to the line not being justified because of, for example, the spacebands lbecoming clogged in the spaceband chute, the locking element will be actuated to stop the machine. The apparatus herein described thus monitors the operation of the Linotype machine and halts it upon the occurrence of any of the above referred to malfunctions.

,An object of the present invention is thus to provide a malfunction detection apparatus for Linotype machines in Vwhich an input pulse provided each time a mat is called for initiates a timing interval at the end of which the machine will be shut down unless a cancelling im` pulse,`indicating properoperation of the machine, is pre` sented to the detecting apparatusV prior to the termination of the timed period. y

A further object of the present invention is to provide an apparatus of the type referred to above, in which the Linotype machine is shut down immediately upon failure of a line to cast.

A further object of the present invention is to provide an apparatus of the type referred to above in which the presentation `of the input pulse to the detecting apparatus is delayed, depending upon the speed of operation of the Linotype machine, so as to clear the cancelling impulse of the preceding operating cycle. p

VA further object of the present invention is to provide an apparatus of the type referred to above in which the Linotype. machine is shut down at` lthe termination of assembly of a line in the event that a mat fails to clear the magazine and sticks in a partially released position.

The full nature of the invention will be lunderstood Yfrom the accompanying drawings and the following de- Linotype machine with Teletypesetter attachment, and' indicating the physical location of certain of the components of the present invention.

Fig. 2 is a fragmentary front view lof a further portion of a Linotype machine illustrating the physical location of further components of the present invention.

Fig. 3 is a fragment-ary, perspective View of la Linotype machine illustrating the location of a further one of the components of the present invention.

' Fig. 4 is a fragmentary plan View of the elevating mechanism of a Linotype machine illustrating the present invention.

Fig. 5 is a fragment-ary, diagrammatic View of the transferring cam of the Linotype machine illustrating the operation -of one of the components of the present invention.

Fig. 6 is a chart indicating certain features of the operational vsequence of the present invention.

Fig. 7 is a schematic circuit diagram of the apparatus embodying the present invention.

Referring initially to Fig. l, there is shown a conventional Linotype machine having attached thereto a Teletypesetter attachment indicated generally at 10. The Linotype machine includes a keyboard 11, an assembling elevator mechanism 12 and an assembler 13. The operation of the above-mentioned components of the Linotype machine is well known to those skilled in the art-and is described in detail in the above-mentioned publications.

The components of the present invention shown in Fig. 1 include the normally open switch 14 having coextensive blades 16 mounted'by means of screws 17 to a keyboard contact bar 18. A shaft 19 is rotatably mounted at 21 upon the bar 18 and carries, by means of legs 22, a bar 23-which is disposed across the front of the keyboard operating mechanism of the Teletypesetter attachment. The shaft 19 further carries a downwardly extending arm 24 which engages the end of one of the Contact carrying blades 16. The shaft 19 is spring biased into a position such that the arm 24 permits the switch 14 to remain in its normally open position. However, each time the Teletypesetter attachment operates the mat releasing linkage of the Linotype machine, the arm 24 is moved so as to mementarily close the .switch 14.

An indicator box 26 is mounted upon the Linotype machine andon its front face is provided with a glow bulb or pilot light 27 having a red translucent shield and asimilar pilot light 28 having a white translucent shield. The indicator box also mounts a release pushbutton 29.

Mounted just to the left of the assembling elevator 12 is Van elevator locking element which includes a solenoid operator 31 and a plunger 32. The solenoid is mounted upon an upwardly extending bar 33 which, at its upper end, provides a pivotal support 34 for a depending stop member 36. A thrust member 37 is pivotally mounted at 38 to the upper end of the plunger. The thrust member extends beneath the stop member and is pivotally connected thereto at 39. As shown in broken lines in Fig. l, downward movement of the plunger results in pivotal movement of the stop member about its pivot 34, thereby projecting it into the path of movement of the assembling elevator of the Linotype machine. In this position it arrests the movement of the elevator mechanism, thereby halting further operation of the Lino type machine.

Referring no-w to Fig. 2, a further portion of the Linotype machine is shown, particularly the magazine 41, the guide chutes 42, and assembler belt 43. It will be understood by those familiar with the operation of Linotype machines that matrices, as they are selected by the keyboard mechanism, drop from the magazine into the guide chutes to be transported by the assembler belt into the assembling elevator. The components of the present invention shown in Fig. 2 are a lighthouse 44 enclosing an electric bulb 46 (Fig. 7) which, through an aperture 47 in the lighthouse casts a light beam, indicated at 45 in Fig, 2, across the path of the mats as they leave the magazine. Mounted so as to be intersected by this light beam is a conventional photocell 48. Thus, each mat, as it is released from the magazine, momentarily interrupts the beam of light directed at the photocell.

Referring to Fig. 3, a further component of the present Vinvention is shown mounted in cooperative relation with the elevator cam shaft which is a part of the Teletypesetter attachment indicated generally at 10. .The component referred to is a normally open switch indicated at 49 and comprising coextensive switch blades 51 and 52 which are secured by means of screws 53 to a mounting bracket 54, which, in turn, is mounted by means of Screw 56 upon an appropriate portion of the Teletypesetter mechanism. The switch blades S1 `and 52 each carry cooperating electrical contacts at their free ends, and the blade 51 is engaged by the elevator cam so as to close the contacts at the end of the assembly operation for each line of type. The operation of the elevator cam in the Teletypesetter attachment is well known to those skilled in the art, and its function is not described herein in detail. Briey, however, it may be pointed out that the elevator cam makes one complete rotation for each line of type assembled and through an appropriate lever mechanism operates the verticalelevator in the Linotype machine. Thus, the switch 49 is normally opened, but is momentarily closed at the end of the assembling operation for each line of type.

f Referring to Fig'. 4, there is shown a portion of the casting apparatus of the Linotype machine. The apparatus shown includes a portion of the pump lever 57 and the pump plunger rod 58. The pump lever has rigidly attached thereto ablock 59 beneath which is positioned a machined surface 61 formed on the end of the long arm 62 of the bell crank pivotally mounted at 63. The short arm 64 of the bell crank is moved as indicated by broken lines in Fig. 4 by a lever 66.` It will be understood by those familiar with the operation of Linotype machines that the surface 61 is maintained beneath the block 59 until a line is to be cast at which time the surface 61v is moved to its broken line position of Fig. 4, against the force exerted by leaf spring 67. When in this position the pump lever is released, permitting the pot cam to actuate the pump lever to complete the casting of the appropriately positioned line of type. Actuation of the pump lever causes it to rotate about its supporting shaft 57a. The component of the present invention which cooperates with the apparatus just described is the normally closed switch 68, having contacts 69 carried by extending resilient4 blades. The switch is mounted by means of a suitable bracket 68a to adjacent portion 7,0 of the casting supporting the shaft 57a. I n Linotype machines the transverse portion of `the pump lever has extending therefrom a lobe or protrusion 70a which is herein utilized to contact one blade of the switch 68 to open its contacts each time the pump lever is actuated. Thus, each time a line is cast, the switch 68 is momentarily opened and, if the surface 61 is maintained beneath the block 59, locking the pump lever against actuation, the switch 68 remains in closed position. It will be understood that the surface 61 is maintained in locking position with relation to the pump lever 57 .whenever the tape passing through the Teletypesetter attachment does not properly justify the line of Vtype or if the spacebands are clogged in the'spaceband chute, thereby preventing their proper assembly in the appropriate line of type.' f

Referring to Fig. 5, there is shown a portion of the transfer cam 71 which forms `a part of the Linotypev machine and serves `to actuate the means for transporting the assembled matrices in proper sequences within the machine. In accord with the present invention a fibre block 72 is mounted upon the inner surface of the cam and cooperates with a switch 73 so as to close the switch momentarily as the block engages the switchy blade 74 during the cam travel. The switch 73 is shown mounted diagrammatically in Fig. 5 and it will be understood that any'suitable' stationary mounting means may be provided. The block 72 is positioned ori the transfer cam so that it closes the contacts of switch 73 at the same time that the switch 68kis opened by the cam 70a (Fig. 4).

Referring now to Fig. 7 the circuit connections and the operation of the present invention will be described.` The power input terminals 76 arefconnected to a 4stabilized' source of`- l'l'O volt A.C., 60 cycle electrical power.' The power input terminals 77 and 78 areconnectedto 4a 127 volt D.C. power source with the `positiveterminal, 78 being grounded. The terminals 76are connected to,2

the primary of a transformer 79 which provides power for the 6 volt A.C. lines 81 and 82 and for the 110 volt A.C. lines 83 and 84. The negative terminal 77 is connected to a bus wire 86. The keyboard switch 14 is connected to the .positive side of .the D.C. linek at 87 and through resistance 88 to one side of a relay coil 89. The other side of the relay coil is connected Iby means of Wire 91 to the supply wire 86. Adelay-timing condenser 92 lis connected across the relay coil and serves the portant functionof delaying ener'gization of the relay coil 89 upon closure of the keyboard switch 14. The capacity of condenser 92. must be matched to correlate with the operating speed of the Linotype machine; thus the capacity of condenser 92 must be increased to provide increased delay when the operating speed of the Linotype machine is increased.

. Energization of relay coilv 89 closes switch 93 which energizes an indicating glow tube 94. Energization of relay coil 89 also closes Iswitch.97 which, by means of wire 98 and resistance 99 charges a condenser 101. Although the input pulse provided by the keyboard switch 14 Vis of momentary duration, the condenser 101 is so sized that it is immediately charged by the input pulse. The condenser 101 is connected to the negative side of the D.C. lineby means of wires 86 and 118 and, by means of wire 117 and variable resistances 102 and 103, is connected in parallel with a condenser 104. After the input pulse,though of only momentary duration, has charged condenser 101, the bleed-off of condenser 101 through variable resistances 102 and 103 serves to charge a condenser 104. As condenser 104 reaches a charged condition, the control electrode 106 of the ygas-filled triode 1,09 is swung positive by means of its connection through wire 107 and resistance 108 to the condenser 104.

, The anode of tube 109 is connected,.by means of wire 111, through a resistance 112 and a'normally closed push button operated switch 113, to the positive side of the line at 114, the switch 113 being operated -by push button 29 previously referred to with reference to Fig. l. The cathode of'the tube 109 is connected to one side of a relay coil 116 and through bleeder resistance 115 to wire 107, The other side of the relay coil 116 is connected by means of wires 117 and V118 to the negative side o-f the D.C. line through wire 86. Relay coil 116 controls a double throw switch having contacts 119 and 121 connecting respectively the actuating coil 31 of the lock element to wire 82 and the lamp 46 to wire 82. When the condensery 104 causes `the tube 109 to fire, the relay coil 116 `will be energized, closing the normally open contacts 119 `of the double throw switch, thereby connecting the actuatingk coil 31 of the lock element, previously described, across the power lines 81 and 82. As previously mentioned, energization of coil 31 serves to lock the elevator mechanism of the Linotype machine, halting its operation. Energization of relay coil 116 also opens the normally closed contacts 121` of the double throw switch, thereby de-energizing the lamp 46, which is housed in the lighthouse 44 and provides the light beam for photocell 48.

From the foregoing it will be evident that with each closure of the keyboard switch 14 an input pulse will be provided. VAfter the delay provided by the condenser 92 the pulse will be applied to condenser 101 and, after a time interval of the order of milliseconds, ltube 109 will fire, 'energizing relay coil 116, and shutting down the Linotype machine. Thisl sequence of events will occur unless, before the termination of the time interval, a cancelling impulse is provided to prevent firing of the tube 109.

This cancelling impulse is provided =by a means now to be described. Across wires 83 and 84 is connected a voltage divider comprising resistance 122, variable resistance 123 and resistance 124. The anode 126 and cathode 127 of a triode tube 128 are connected across a portion of the voltage.. divider, these connectionsbeing positive, causing tube 128 to conduct, Athereby energizing relay coil 131. Energization of relay coil 131 closes the that as long as the photocell 48 is illuminated by the lamp 46, tube 128 will be maintained Anonconductive.

Upon interruption of the light beam, cell 48 will become nonconductive, swinging the control electrode 137 switch 138 which energizes relay coil 139 through the positive ground connection 141, wire 142, resistance 143, wire 144, and via wires 117 and 118 to wire 86. The red pilot bulb 27 is connected to switch 138 by means. of wires 142 and 146, the other side of the'bulb being: connected to the line wire 86 through resistance 147 and wire 148. Closure of switch 138 thus also energizes the red pilot bulb 27 through wire 146, resistance 147 and wire 148. The contacts of switch 138 are protected by parallel connected resistor 140.

Energization of relay coil 131 also closes switch 149 Which by means of the circuit through wires 151, 152, resistance 153, Wire 107 and resistance 108, discharges the condenser 104. Switch 154 connects wire 144 to wire 98 via the resistor 156 and wire 157, and energization of relaycoil 139 closes switch 154 which, by means of wire 144, resistance 156 and wire 157 provides a discharging circuit for the condenser 101. Energization of relay coil 139 also closes switch 158 which, by means of wire 159, wire 161 and resistance 162, provides a circuit from the control electrode 106 of tube 109 to the positive ground connection 163 which, however, is closed only upon actuation to closed position of the switch 49 previously referred to with reference to Fig. 3.

From the foregoing it will be evident that the proper release of a mat from the magazine in response to operation of the mat releasing linkage by the Teletypesetter will momentarily interrupt the beam from lamp 46 providing a cancelling impulse which discharges condensers 101 and 104 before the control electrode 106 can cause tube 109 to fire, thereby preventing energization of the lock element 31 and permitting operation of the Linotype machine to proceed. Each input pulse will be characterized by a momentary illumination of amber pilot bulb 94, and each cancelling impulse will be characterized by a momentary illumination of the red pilot bulb 27.

The casting pump lever switch 68 and the transfer cam switch 73, referred to with reference to Figs. 4 and 5, respectively, are connected to positive ground at '163 and by means of wire 164 to one side of a relay coil 166. The other side of the relay coil is connected by means of wire 167 to the wire 107. Should the switches 73 and 68 be closed simultaneously, indicating that a line has -failed to cast (because of, for example, the spacebands being clogged in the spaceband chute), the control electrode 106 will be swung positive lby means of wire 167, causing tube 109 to fire and energizing the lock element 31 stopping operation of the Linotype machine. Upon tiring of tube 109, relay coil 166 will be energized closing the switch 167 which provides a holding circuit for the relay to the positive ground connection 114, subsequent manual running through of the machine will not, therefore, rie-energize relay coil 166. Energization of relay coil 166 also closes a switch 168 which, by means of positive connection 114, wire 169, resistance 171, wire 148 and wire 86, energizes the white pilot bulb 28. After the malfunction thereby indicated has been corrected, the push button 29 may be depressed, opening switch 113 and breaking the holding circuit to relay coil 166 andV rendering tube 109 nonconductive. Operation of the Linotype machine may then be resumed.

A table of preferred values for the various resistors and capacitorsL described is set out below together with the preferred number' designations ofthe principal tubes use?! 'nlbelbirclli Component: Value 1022` kilohms-- l2 12s d0 2 124 ohms.-- 2700, 88 kilnhms` 15 153 do 10 162 do 2.2 156 'do 10 108 kilnhm 1 115 megohms 44 143 kilohms l5 103 do 200 102 do 200 140 do 220 147 dn 47 171 do 47 112 ohms 820 99 kilohms-- 10 92 microfarads l-4 104 microfarad 1 101 microfarads..- 2,-3 136 do 1.5

Tube: Number 128 2050-1 109 OA4G From the foregoing, it will be evident that the circuit described provides safeguards for the occurrence of several malfunctions. If a mat fails to fall in response to operation of the mat releasing linkage, condenser 104 will fire tube 109, causing the Linotype machine to stop. If a mat is stuck part way out of the magazine so as to continuously interrupt the light beam, relay switch 158 will remain closed and upon the momentary closure of switch 49 at the termination of assembling of the line, tube 109 will be immediately fired, causing the Linotype machine to stop. Illumination of the red pilot bulbI 27 will indicate that the machine has stopped because of vthe occurrence of either of the two malfunctions above described. Should a line fail to cast, causing simultaneous closure of switches 73 and 68, tube 109 will be fired, thereby halting operation of the Linotype machine. When the machine is stopped because of this type of malfunction, this fact will be indicated by illumination of both red pilot ybulb 27 and white pilot bulb 28. Proper operation and adjustment of the circuit is -facilitated by the amber pilot bulb 94 which blinks with each input pulse and by red pilot bulb 27 which blinks with each cancelling pulse.

Fig. 6 illustrates the importance of the delay of the input pulse provided by the condenser 92. This ligure comprises a chart divided into time intervals of the order of, for example, 110 milliseconds. Each interval has set out above it, as an example, one letter of the three letter word the Assuming initially that condenser 92 and its input pulse delaying feature were omitted, the input pulse for the first letter of the word the would be initiated immediately.upon closure of switch 14. As indicated lon the chart the input pulse designated by the solid bar 176 would start at the cycle dividing line 177. A predetermined time after closure of switch 14, this period being relatively unchangeable and dictated by the mechanics of the mat releasing mechanism, a cancelling pulse indicated by solid line block 17S will occur. As long as the machine is operated at medium or slow speed so that the start of the next input pulse is not initiated until after the completion of the preceding cancelling pulse, proper operation of the machine will be maintained. In other words, with reference to the chart of Fig. 6, as long as the distance between the cycle boundaries, designated at 177 and 179, is suiiet to` place the liner179 to the right of the terminus of block 173, operationy of the machine will proceed satisfactorily.

However, when4 the machine is'run at high' speed, so that the cycle is of the order of milliseconds duration, sincethe distance indicatedv atfa in Fig. 6 is unchangeable and fixed by themechanics of the' mat releasing mechanism, thefcancelling pulses will now overlapV or4 hang over the cycle boundaries. The latter portion of' alcancelling pulse will thereby cancel a portion of the succeeding input pulse, as indicated at in Fig. 6, leaving Ian'unsatisfactorily foreshortened input pulse 181.

Since the first letterrin a word, as for example the in theflis preceded by a space (release of spacebandsV createlno cancelling pulse), the first letter in each Word would, under ythese conditions, provide aV full input pulse while each following letter would provide a foreshortened input pulse.

In order to eliminate this, irregularity of the input pulses in high speed operation ofthe machine, the charging and discharging of condenser 92 serves to delay the energization of relay coil 89., and hence the start of an input pulse, for a time interval after closure of switch 14. Further, discharge of the condenser 92 after the opening of switch 14 delays the deenergization of relay coil 89 for a time interval subsequent to the opening of switch 14. With reference -to Fig. 6, this results in shifting rightwardly the input pulse 176 to its broken line position 176:1, a similar rightwardly shifted input pulse being also shown at 182. Thus, although closure of switch 14 occurs at the cycle boundaries 177 and 179, the input pulse,

representing a properly positioned input pulse, and blocks 183 and 184, indicating the preceding and subsequent cancelling pulses.

It will thus be apparent that the proper positioning of.

the input pulse within a cycle, so that it is not obliterated in part by the hangover of the cancelling pulse from the preceding cycle is a vital factor in automatic operation of such machines as slug linecasting machines at high speed. The input pulse shifting means represents an important feature of the present invention.

From the foregoing it 'will be evident that the devicel embodying the present invention provides important economies in the operation of Teletypesetter-equipped Linotype machines. These economies are brought about by saving in correction time resulting from machine errors,

Y by reducing revised proof-pulling and proofreading time,

and by saving press time delays caused by needless corrections. The present invention provides for shutting down operation of the Linotype machine upon the occurrence of any one-of several common malfunctions and provides indicating means for designating which type of malfunction caused the machine shutdown. By means of the delay provided for the input pulse the apparatus of the present invention is particularly adapted to high speed Linotype machine operation.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are td be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A malfunction detection circuit for slug linecasting machines having an automatic operating attachment, said circuit including a locking element adapted when electrically energized to halt operation of the machine, a control tube having an anode, cathode and control electrode and adapted to energize said locking element upon being rendered conductive, timing means for iringsaid '9 cntol'tube a timed period subsequetto receipt of'an inputpulse, said timing'mens including a first condenser charged by said input pulse and a second condenser charged by the .discharge of said first condenser upon termination of the input pulse to thereby raise said control electrode to firing potential, means for discharging said condensers prior to the termination of said timed period upon receipt of a cancelling impulse, said lastmentioned means including discharge circuits vfor said condensers completed upon receipt of said'cancelling impulse,'means 4for applying said cancelling impulse to said discharge circuits including a photoclectricl device operable to provide `said cancelling impulse upon proper response of the linecasting machine to operation o'f its mat releasing linkage, means for providing said input pulse upon operation of the mat releasing linkage of the linecasting machine, and means for'delaying the application'ofsaid input pulsetosaid first condenser including electromagnetically operated switching means connected in series' therewith, a timing condenser connected in parallel with the electromagnetic operator for said switchingmeans, ther charging time of said vtiming condenser thereby `delaying energiz'ationlof said/electromagnetic operator to permit said input pulse -to clear the cancelling pulse of the preceding operating cycle.

2. A malfunction detection circuit as claimed in claim 1, having circuit means for tiring said co'ntrol tube in dependently of said condensers, a rst normally open switch momentarily closed at the completion of the assembly of each line of type, a second normally open switch closed for the duration of said cancelling pulse, said first and second switches being connected in series in said circuit means for iiring said control tube at the completion of the assembly of aline of type which is defective because of the incomplete delivery of a mat providing a prolonged cancelling pulse.

3. A malfunction detection circuit for slug linecasting machines having an automatic operating attachment, said circuit including a locking element adapted when electrically energized to halt operation of the machine, a control tube having an anode, cathode and control electrode and adapted to energize said locking element upon being rendered conductive, timing means for tiring said control tube a timed period subsequent to receipt o'f an input pulse, said timing means including a condenser charged by said input pulse to thereby raise said control electrode to tiring potential, means -for discharging said condenser prior to the termination of said timed period upon receipt of a cancelling impulse, said lastmentio'ned means including a discharge circuit for said condensers completed upon receipt of said cancelling impulse, means for applying said cancelling impulse to said discharge circuit including a photoelectric device operable to provide said cancelling impulse upon proper response of the linecasting machine to operation of its mat releasing linkage, means for providing said input pulse upon operation of the mat releasing linkage of the linecasting machine, and means for delaying the application of said input pulse to said condenser including electro-v magnetically operated switching means connected therewith, a timing condenser connected in parallel with the electromagnetic operator for said switching means, the charging time of said timing condenser thereby delaying energization of said electromagnetic operator to permit said input pulse to clear the cancelling pulse of the preceding operating cycle.

4. A malfunction detection circuit for slug linecasting machines hav-ing an automatic operating attachment, said circuit including a locking element adapted when -energized to halt operation of the machine, a control tube having an anode, cathode and control electrode and adapted to energize said locking element upon being rendered conductive, timing means for ring said control tube a timed period subsequent to receipt of an input pulse, said timing means including a rst condenser ."1'0 charged-Byzsaid "input pulse andY a second condenser' chargedA by theVv discharge of'said first condensernpon termination of the input pulse to thereby raise said control electrode to firing potential, means for discharging saidV condensers prior toY the termination of said timed period upon receipt of a cancelling impulse, said lastmentionedmeansV including discharge circuits for said condensers completed upon receipt of said cancelling impulse, means for applying Vsaid cancelling impulse to said discharge circuits including sensing means operable to provide said cancelling impulse upon proper response of the linecasting machine to operation of its Vmat releasing linkage, vrneansfo'r providing said input pulse upon operatir'm.I ofv theV mat releasing linkage of the linecasting machine, land means for delaying the application of said input pulse to said rst condenser to permit said input pulse to clear the cancelling pulse of vthe preceding operat- 'ing cycle.

'"5. A malfunction detection circuit for slug linecasting machines having an automatic operating attachment, said circuit including :a'locking element adapted when electrically energized to halt operation of the machine, a control tube--havinganfanode, cathode and control electrode and adapted to energize 'said Vlocki-ng element upon being rendered conductive, timing means for firing said control tube a timed period subsequent to receipt of an input pulse, said timing means including a irst condenser charged by said input pulse and a second condenser charged by the discharge of said rst condenser upon termination of the input pulse to thereby raise said control electrode to tiring potential, means for discharging said condensers prior to the termination of said timed period upon receipt of a cancelling impulse, said last-mentioned means including discharge circuits for said condensers completed upon receipt of said cancelling impulse, means for applying said cancelling impulse to said discharge circuits including means operable to provide said cancelling impulse in response to proper operation of the linecasting machine, and means for providing said input pulse upon operation of the mat releasing linkage of the linecasting machine.

6. A malfunction detection circuit for slug linecasting machines having an automatic operating attachment, said circuit including a locking element adapted when electrically energized to halt operation of the machine, a control tube having an anode, cathode and control electrode and adapted to energize said locking element upon being rendered conductive, timing means for firing said control tube a timed period subsequent to receipt o'f an input pulse, said timing vmeans including a condenser charged by said input pulse to thereby raise said control electrode to firing potential, means for discharging said condenser prior to the termination of said timed period upon receipt of a cancelling impulse, means 4for generating said cancelling impulse including a photoelectric device operable upon proper mat delivery by the linecasting machine, means for providing Isaid input pulse upon actuation of the mat delivery mechanism of the linecasting machine, and means for delaying the application of said input pulse to said condenser including electromagnetically operated switching means, a timing co'ndenser connected in parallel with the electromagnetic operator for said switching means, `the charging time of said timing condenser delaying energization of said electromagnetic operator to permit said input pulse to clear the cancelling pulse of the preceding operating cycle.

7. A malfunction `detection circuit as claimed in claim 6, having circuit means for firing said control tube independently of said rst-mentioned condenser, a rst normally open switch momentarily closed at the completion of the assembly of each line of type, a second normally open switch closed for the duration of said cancelling pulse, said rst and second switches being connected in series in said circuit means for iin'ng said control tube at the completion of the assembly of a line 1 1 livery of a mat providing a prolonged cancelling pulse.

8, A malfunction detection circuit as claimed in claim 6, having circuit means for iiring said control tube independently of said cancelling pulse, switching means forming a part of said circuit means and closed upon failure of a line to cast, said locking element being thereby operated upon failure of a line to cast independently of proper mat delivery.

9. A malfunction detecting circuit as claimed in claim 8, having indicating means for indicating Whether said locking means has been actuated by the absence of a cancelling impulse or by failureof a line to cast.

10. A malfunction detection circuit for sluglinecasting machines including a lockingelement adapted when actuated to halt `operation of the machine, controly means for actuating said locking element a predetermined time subsequent to application ofv an input pulse to said con,- Vtrol means, and means operable to prevent actuation of said locking element by said control means including an element responsive to proper operation of the machine for providingv a cancelling pulse to said control means, and time delay means for delaying the application of said input pulse to said control means to permit clearing of the cancelling pulse ofL the preceding'cycle,

1l. A malfunction detection circuit for automatically operated machinery includingrv a locking element adapted when actuated to halt operation of the machine, control means fo'r actuating said `locking element a predetermined time subsequent `to application of an input pulse to. said control means, and means operable to prevent actuation of said. locking element by said control means including an element responsive to proper operation of the machine for pro'viding a cancelling pulse to said controlV means, and time delay means for delaying application of said input pulse to said control means to permit clearing of the cancelling pulse. of the preceding cycle.

References Cited in the le of this patent UNITED STATES PATENTS 'ne' l' gw. 

